Dorothy Marshall said she didn't know what the plant was from the start. She sounded very excited over the phone as she described a cactus she got in 1955, shortly after she married Bob.

The cactus - she calls it a mystery cactus - did not bloom at first for around 30 years.

"I almost let this cactus die several times, but then I would think grandma gave it to us so I can't let that happen," Dorothy shared as she pointed to the 2-4 foot long, spidery-looking succulent.

Then suddenly - well, waiting 30 years is not that sudden - the plant bloomed.

She asserts she did not fertilize it, add soil, or do anything out of the ordinary at that point.

"It was one bloom, then nothing," Dorothy said.

After moving to town and getting placed in a west window with filtered light, the cactus had another bloom, which lasted several days. Once the bloom died, a second bud appeared; bloomed, then died.

'It waited for the one bloom to die before it started growing another one."

Dorothy said she was so intrigued, she painted a picture of the plant with bright red flowers. The painting was on display in one of Arts Rolla's monthly exhibits at Rolla's Health and Recreation Center. Admirers either identified the mystery cactus as a Christmas cactus, or asked if it was a plant Dorothy had imagined.

"I do make some things up in my paintings," she said as she showed me several flower paintings hanging over the sofa in her living room.

The flowers were a good hint since they look at lot like the white flowers on my night cereus, both members of the Epiphyllum family.

According to Dave's Garden, Dorothy's cactus is an orchid cactus Disocactus ackermannii. This family of cactus live on the surface of other plants without taking away nutrients from their host plants, usually in shady tree nooks and rock crevices in Central and South America.

Also known as a strap cactus, day-blooming flower petals are equal size and pointed, similar to smaller, Easter cactus bloom.

Stems have roots that will self-start in any nearby pot, as Dorothy's daughter can attest.

Tiny needles at the other end are hard to remove so Dorothy tries not to inadvertently collect any as she grooms the plant.